Electric reversing-gear.



0. KRAMER.

ELECTRIC REVERSING GEAR.

APPLICATION FILED MAYlO, 1909.

Inventor Christian Kramer,

Witnesses:

His fittorne g.

Patented Aug. 26, 1913.

MQZLQQ UNITED STATES PATENT OFFICE.

CHRISTIAN KRAMER, OF FRANKFORT-ON-THE-MAIN, GERMANY, ASSIGNOR TO THEFIRM OF FELTEN 8t GUILLEAUME-LAHMEYERWERKE AKTIEN GESELLSCHAFT, OF

FRANKFOBT-ON-THE-MAIN, GERMANY.

ELECTRIC REVERSING-GEAR.

Specification of Letters Patent.

Patented Aug. 26,1913.

Application filed May 10, 1909. Serial No. 495,030.

T 0 all whom it may concern):

Be it known that I, CHRISTIAN KRAMER, a subject of the German Emperor,and a resident of Frankfort-on-the-Main, Germany, have invented certainnew and useful Improvements in Electric Reversing-Gears, of which thefollowing is a specification.

This invention relates to dynamo electric machinery and in particular tomeans for driving. a motor at various speeds in either direction.

In certain classes of motors, especially in motors used' for drivingsubmarines, it is necessary that the motor bereversed quickly. \Vherethe speed of the motor is varied by a reversible counter-electromotiveforce machine the system is open to the objection that there is aretardation of the time conshort circuit with a stant of the field, theexcitation following only very slowly the value given by the regulator.Therefore when the motor is suddenly reversed there is produced a directpressure equal to double the circuit pressure.

In accordance with this invention the circuit is provided with meanswhereby the value of the current is maintained constant irrespective ofthe resistance of the circuit,

and means are provided for varying the value of the constant current andthus the speed of the motor.

Preferably, a regulating dynamo-electric machine is connected with itsarmature in series circuit with a source of constant potential current.The regulating machine may be provided with a field in series with thecircuit, a second field connected across its armature, and a third fieldconnected across a source of constant potential, preferably the sourceof current. The second and third fields are connected to produce amagnetization which will produce an electro-motive force in the sainedirection as the source, while the first or series field produces amagnetization which will produce an electro-motive force opposite tothat of the source. These fields will determine the value of the currentand will maintain that value constant. The motor can therefore be safelyreversed, and 7 can be stopped by simply short-circuiting its field,without the objection above referred to, since the current is maintainedconstant. The third field is Imotive force of the source 6. field Itwill produce a magnetization which will produce an electro-motive forcewhich .is opposed (0 provided with a regulator to vary the value of thecurrent and therefore the speed of the motor.

In the drawing the figure is a diagram showing this invention.

Referring to the drawing 6 is a source of current, preferably a storagebattery, which is connected in circuit with the driving motor m whichcan be used for driving any suitable mechanism. In the drawing it isshown as driving the propeller s. The motor m is provided with a field dwhich in this case is a series field connected in the circuit by meansof a reversing switch u. The regulating machine I) for regulating thespeed of the motor has its armature connected in series circuit with thesource of current 6, and the motor m and is driven by a driving motor wconnected across the terminals of the source 6. The regulating machine bis provided with a series field 72, connected in series with the maincircuit, a shunt field 9 connected across the armature -of the machineand a third field f connected across a source of constant potential, the.source of constant potential being in the specific embodiment shown,the source of current e. The field f is provided with a regulator 1' fora purpose hereinafter to be described.

The fields g and f produce a magnetization which will produce anelectro-motive force in the same direction as the electro- The seriesthe electro-motive force 6. These fields are so proportioned that whenthe value of the current in the circuit is normal, the field it willneutralize the fields g and f. If therefore the current in the circuitshould for any reason rise, the field vl1, will over-balance g and f andtherefore the voltage of the circuit will drop and the current will bereduced to its former value. In a similar manner if the current in thecircuit should drop, 9 and f will over-balance h, the reverse actionwill take place, and the current will remain constant. The value of thisconstant current may be varied by means of the regulator 1- and anyposition of the regulator 1' will determine the' value -of the constantcurrent and this value will remain constant irrespective of the resist.-ance of the circuit.

The speed of the motor m may be varied by varyin the value of thecurrent traversing the circuit, that is, by ad usting the regulator 1'.The motor we may be reversed in any suitable manner well known to thoseskilled in the art. In the present embodiment the motor, which is aseriesmotor, is reversed by reversing the field leads by means of thereversing switch a. Since the current in the circuits is maintainedconstant, the objectionable short-circuit caused by -reversing theordinary counter-electromotive force, is not found here. Ihe motor maybe stopped by simply short-circuiting the field d or by opening thecircuit or in any other manner well known to those skilled in the art.In the specific construction shown the motor m is shown as a seriesmotor. It is not necessary however that this be a series motor for. itmay equally well be a shunt or a compound motor. The field of thedynamo-electric machine excited by its own means and that excited from aseparate source can be replaced by a field supplied by the sum of thepressures of the separate and its own excitation. It is further obviousthat various changes may be made without departing from the spirit ofthis invention and it is therefore to be understood that this inventionis not to be limited to the specific construction shown and described.

Having thus described the invention what I claim is:

1. The combination with a source of current, of a motor connected tosaid source, a regulating dynamo-electric machine connected in circuitwith said source and motor, means for causin said dynamo-electricmachine to automatlcally maintain the current passing through said motorof a predetermined constant value, and controller means for varying thevalue of the current so maintained to vary the speed of the motor.

2. The combination with a source of current, of a motor connected tosaid source, a regulating dynamo-electric machine connected in circuitwith said source and motor, means for causin said dynamo-electricmachine to automatically maintain the current passing through said motorof a predetermined constant value, and controller means controlling saiddynamo-electric machine for varying the value of the current somaintained to vary the speed of the motor.

3. The combination with a source of current, of a motor connected tosaid source, a dynamo-electric machine connected in circuit with saidsource and motor, a field winding for said dynamo-electric machinecarrying current proportional to the current in said circuit, a secondfield winding connected across the armature of said dynamo-electricmachine, and means for rendering the resultant field of said machinezero when a predetermined current traverses the circuit.

4. The combination with a source of current, of a motor connected tosaid source, adynamo-electr-ic machine connected in circuit with saidsource and motor, means for causing said machine to automaticallymaintain the current passing through said motor of a predeterminedvalue, comprising a differential field winding for said dynamo-electricmachine, and means for rendering the resultant field of said machinezero when such a predetermined current traverses the motor.

5. The combination with a source of current, of a motor connected tosaid source, a dynamo-electric machine connected in circuit with saidsource and motor, a field winding for said dynamo-electric machinecarrying current proportional to the current in said circuit, a secondfield winding connected across the armature of said dynamoelectricmachine, means for rendering the resultant field of said machine zerowhen a predetermined current traverses the circuit, and means to varythe value of the current.

6. The combination with a source of current, of a motor connected tosaid source, a dynamo electric machine connected in circuit with saidsource and motor, a field winding for said dynamo-electric machinecarrying current proportional to 'the current in said circuit, a secondfield winding connected across the armature of said dynamo-electricmachine, and a third field windin connected across a source of constantpotential, the second and third field windings neutralizing the firstfield winding when a predetermined current traverses the circuit;

7. The combination with a source of current, of a motor connected tosaid source, a dynamo-electric machine connected in circuit with saidsource and motor, a field winding for said dynamo-electric machinecarrying current proportional to the current in said circuit, a secondfield winding connected across the armature of said dynamoelectricmachine, a third field winding connected across said source, and aregulator for said third field winding, the second and third fieldwindings neutralizing the first field 1 circuit, a second field windingconnected across the armature of said dynamo-electric machine, a thirdfield winding connected across said source, a regulator for said thirdfield winding, the second and third field windings neutralizing thefirst field winding when a predetermined current traverses the circuit,and means for reversing the motor.

9. The combination with a source of current, of a motor connected tosaid source, a dynamo-electric machine having its armature connected incircuit with said source and motor, a field winding for saiddynamoelectric machine excited by a current pro ortional to thatsupplied to the motor, an arranged to induce in said armature anelectromotive force opposed to that of the circuit, and means forsetting up a ma etic field in said dynamo-electric machine in oppositionto the first field winding by the joint action of the terminal pressureof the dynamo-electrio machine and another source of electromotiveforce.

10. The combination with a source of current, of a motor connected tosaid source, a dynamo electric machine having its armature connected incircuit with said source and motor, means for setting up in said dynamoelectric machine a constant field, means for setting up a fieldproportional to the current traversing said motor, and means for sett'up a field proportional to the voltage of sai dynamo-electric machine.

11. The combination with a source of current, of a motor connected tosaid source, a dynamo-electric machine havin its armature connected incircuit with sai source and motor, means for setting up in saiddynamoelectric machine a constant field, means for setting up a fieldproportional to the current traversing said motor, means for setting upa field proportional to the voltage of said dynamo-electric machine, andmeans for varying the value of said constant field.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHRISTIAN KRAMER.

Witnesses:

JEAN GRUND, Enwnr DIPPBELY.

